Re: Writing Rules

[Kevin Ryde]

"Rev. Jonathan T Sage" <address@hidden> writes:
> 
> #define IPL_VERSION = "IP Filter: v3.x.yy"
> 
> I need to define IPF_4_3 if x=4, and not define it if x=3.

Perhaps something like (untested),

    if grep "IP Filter: v3\.4\." /usr/include/netinet/ipl.h >/dev/null; then
      AC_DEFINE(IPF_4_3, 1, [Define for IP Filter v3.4.x])
    fi

(Though whether it's particularly robust to be grepping particular
include files is another matter.)